The earth is surrounded by <em>a layer of</em> gases called the <em>atmosphere</em>. The atmosphere is very <em>important </em>to life on <em>Earth</em> and does many <em>things</em> to help protect life and help<em> life </em>to survive.
The atmosphere absorbs the <em>heat</em> from the <em>Sun </em>and keeps the heat <em>inside</em> the atmosphere helping the <em>Earth </em>to stay warm, called the <em>Greenhouse </em>Effect.
Pond water contains a variety of plant and animal life. While some are visible to the plain eye, others require a microscope to observe them. For example, there's bacteria, protozoa, hydras, algae, and arthropods. You will have the opportunity to see a number of microorganisms from both the plant and animal kingdom.
Independent variable: The difference in the amount of water the plants are fed. Dependant variable: the health of the plants . Control variable: temperature, amount of sunshine, type of plant amount of co2,